short mentions should have full title (#396)

quick fixup to #395

routes/_components/status/StatusMentions.html

@@ -6,7 +6,7 @@
            
         {/if}
         <a href="/accounts/{mention.id}"
-           title="@{mention.username}"
+           title="@{mention.acct}"
            focus-key="status-mention-link-{uuid}-{mention.id}">
           @{mention.username}
         </a>